如何强制在图表顶部使用科学记数法

Question

我正在处理一堆图和组图，有时会发生一些奇怪的事情。我正在根据数据表进行绘图，当需要确定 y 刻度距离时，有时科学符号“位置合适”（至少对于我个人的需求而言），有时则不是。这里有两张图片：

如您所见，第一幅图将10^-2右侧放在顶部，而第二幅图代表了我想指出的“问题”。有没有办法强制科学符号留在图表顶部？我不明白算法如何决定放置符号。

下面是我当前正在使用的 groupplot 结构：

\documentclass{article}
\usepackage[dvipsnames]{xcolor}
\usepackage{pgf,pgfplots,pgfplotstable}
\pgfplotsset{compat=newest}
\usepgfplotslibrary{colormaps}
\usepgfplotslibrary{groupplots}

\begin{document}


\begin{figure}[htbp]
    \centering
    \pgfplotstableread{data/v3/b1/vel/vzt.dat}{\DataTableA}
    \pgfplotstableread{data/v3/b2/vel/vzt.dat}{\DataTableB}
 
    \begin{tikzpicture}[scale=0.9]
        \begin{groupplot}[group style={
        group name=vztcompcross,
        group size=1 by 2,
        xlabels at=edge bottom,
        ylabels at=edge left,
        vertical sep=4em
        },
        xmin = 0, xmax = 30,
        ymin = -0.09, ymax = 0.06,
        xtick distance = 5,
        ytick distance = 0.03,
        xlabel={$time\;[s]$},
        ylabel={$V_z\;[km/s]$},
        grid = both,
        grid style = {dotted},
        minor tick num = 1,
        major grid style = {lightgray!75},
        minor grid style = {lightgray!75},
        width = 0.85\textwidth,
        height = 0.50\textwidth,
        %scale only axis,
        %legend cell align = {left},
        %legend pos = north east,
        legend style={at={(0.5,-0.3)},
        anchor=north,legend columns=4},
        legend cell align = {left},
    ]
     

    \nextgroupplot[title={title1}]
     

    \addplot[smooth, black, ultra thick] table [x = {t1a}, y = {vz1a}] {\DataTableA};
    \addplot[smooth, Lavender, very thick] table [x = {t1b}, y = {vz1b}] {\DataTableA};
    \addplot[smooth, Violet, very thick] table [x = {t1c}, y = {vz1c}] {\DataTableA};
    \addplot[smooth, Emerald, dotted, ultra thick] table [x = {t2}, y = {vz2}] {\DataTableA};




    \nextgroupplot[title={title2},
    xmin = 0, xmax = 15,
    ymin = -0.12, ymax = 0.06,
    ytick distance = 0.03,
    legend entries={n1(k),n1(k-2),n1(k-4),n2(k),n2(j),n2(j+1.5),n2(j+3)},
    ]

    \addlegendimage{black, no markers, very thick}
    \addlegendimage{Lavender, no markers, very thick}
    \addlegendimage{Violet, no markers, very thick}
    \addlegendimage{Emerald, dotted, no markers, ultra thick}
    \addlegendimage{Apricot, no markers, very thick}
    \addlegendimage{RedOrange, no markers, very thick}
    \addlegendimage{MidnightBlue, no markers, very thick}


    \addplot[smooth, Apricot, ultra thick] table [x = {t1a}, y = {vz1a}] {\DataTableB};
    \addplot[smooth, RedOrange, very thick] table [x = {t1b}, y = {vz1b}] {\DataTableB};
    \addplot[smooth, MidnightBlue, very thick] table [x = {t1c}, y = {vz1c}] {\DataTableB};
    

    
 
\end{groupplot}
\end{tikzpicture}
\caption{some random caption}
\end{figure}

\end{document}

Answer 1

好的，我刚刚制作了一些虚拟表来试用您的代码。您需要添加的唯一一行是scaled y ticks = base x:y。对于DataTableB，在这种情况下，您必须手动传递scaled y ticks = base 10:2，然后强制-0.12显示为，-12从而允许使用公因数进行缩放。我注释掉了导致无法编译或不需要给出解决方案的行。

\documentclass{article}
\usepackage[dvipsnames]{xcolor}
\usepackage{pgf,pgfplots,pgfplotstable}
\pgfplotsset{compat=newest}
\usepgfplotslibrary{colormaps}
\usepgfplotslibrary{groupplots}

\begin{document}


\begin{figure}[htbp]
    \centering
    \pgfplotstableread{table.txt}{\DataTableA}
    \pgfplotstableread{table.txt}{\DataTableB}
 
 
    \begin{tikzpicture}[scale=0.9]
        \begin{groupplot}[group style={
        group name=vztcompcross,
        group size=1 by 2,
        xlabels at=edge bottom,
        ylabels at=edge left,
        vertical sep=4em
        },
        xmin = 0, xmax = 30,
        ymin = -0.09, ymax = 0.06,
        xtick distance = 5,
        ytick distance = 0.03,
        xlabel={$time\;[s]$},
        ylabel={$V_z\;[km/s]$},
        grid = both,
        grid style = {dotted},
        minor tick num = 1,
        major grid style = {lightgray!75},
        minor grid style = {lightgray!75},
        width = 0.85\textwidth,
        height = 0.50\textwidth,
        %scale only axis,
        %legend cell align = {left},
        %legend pos = north east,
        legend style={at={(0.5,-0.3)},
        anchor=north,legend columns=4},
        legend cell align = {left},
        scaled ticks=true
    ]
     

    \nextgroupplot[title={title1}]
     

    \addplot[smooth, black, ultra thick] table [x = {t1a}, y = {vz1a}] {\DataTableA};
    %\addplot[smooth, Lavender, very thick] table [x = {t1b}, y = {vz1b}] {\DataTableA};
    %\addplot[smooth, Violet, very thick] table [x = {t1c}, y = {vz1c}] {\DataTableA};
    %\addplot[smooth, Emerald, dotted, ultra thick] table [x = {t2}, y = {vz2}] {\DataTableA};

     \nextgroupplot[
     scaled y ticks=base 10:2 %<----------- Here
     title={title2},
    xmin = 0, xmax = 15,
    ymin = -0.12, ymax = 0.06,
    ytick distance = 0.03,
   % legend entries={n1(k),n1(k-2),n1(k-4),n2(k),n2(j),n2(j+1.5),n2(j+3)},
    ]

%    \addlegendimage{black, no markers, very thick}
%    \addlegendimage{Lavender, no markers, very thick}
%    \addlegendimage{Violet, no markers, very thick}
%    \addlegendimage{Emerald, dotted, no markers, ultra thick}
%    \addlegendimage{Apricot, no markers, very thick}
%    \addlegendimage{RedOrange, no markers, very thick}
%    \addlegendimage{MidnightBlue, no markers, very thick}
%
%
    \addplot[smooth, Apricot, ultra thick] table [x = {t1a}, y = {vz1a}] {\DataTableB};
%    \addplot[smooth, RedOrange, very thick] table [x = {t1b}, y = {vz1b}] {\DataTableB};
%    \addplot[smooth, MidnightBlue, very thick] table [x = {t1c}, y = {vz1c}] {\DataTableB};
%    
%
%    
% 
\end{groupplot}
\end{tikzpicture}
\caption{some random caption}
\end{figure}

\end{document}

通过设置scaled y ticks=base 10:1，您可以获得